Piston



Nov. 27 1923. L47559 R. WOODRUFF PIsToNA Filed Dec. 22. 1921 2 She`ets-Sheet 2 paitenteel Nov. 27, 1923.

,. rra stares RUSSELL J'. WOODRUFF, 0F CLEVELAND, OHIO.

- Heron.

application filed December 22, 1921.

To all wim/m t fmafg/ concern.'

Be it. known that Rossa-LL J. lVo. nrrrr. a citizen e' the United States, resildent ot' Cleveland, county of Cuyahoga, and

State of (lhio, have invented vnew and useful Improvements in Pistons, ol which the following isv a specification, the principle ot the invention being herein explained, and the best` mode in which l have conteml plated applying that principle, so as 'to distinguish it from other inventions.

My invention relates to'pistons and particularly to means of this character adapted for use in internal combustion engines. The purpose of the invention is to design a piston which shall have an e'llicient bearing in the cylinder; which shall provide satisfactorily quick cooling of the piston head; and which shall provide automatic adjustment for the differential in thel heating and cooling ot the piston skirt and pistonl head. This piston is a composite structure and possesses advantages incidentto the aforedescribed design which will be hereinafter discussed in detail.

rilhe annexed drawings and the following description set forth in detail certain means embodying my invention, the disclosed means, however', constituting but one ot the 3o various t'orins in which the principle of the invention may be employed.

in said annexed drawings:

Figure l represents an elevation of my improved piston, the piston skirt being shown in section and the usual wrist pin and connecting rod being omitted;

Figure 2 represents a horizontal section. laken in the planes indicated hy the line liv-ll, Figure 3;

Figure 3 represent-s a vert-ical section, taken in the planes indicated by 'the'line lill-Ill, Figure 2; and

Figure 4E represents a vertical section, taken in the plane indicated by the line 'IV-l V, Figure 3.

Referring to the annexed drawings in which the several elements are indicated by the same respective ordinals in the different Views, the wall of an internal combustion engine. cylinder is suggested'by the ordinal '1, within which is guided the skirt 2 of my improved piston. This skirt 2 may he of any suitable wear-resisting material having a relatively low coellicient oll thermal expansion and a rela-tively low heat conductivity, such as cast-iron or a section y ing together theskirt 2 and head f in Figure 3.

Serial No. 524,055.

of steel tnbing,and for the purposes of illustration in this specification, l shall describe this skirt 2 as made of cast-iron. The head 3 of my improved piston is formed of an alloy or a metal having a relatively high coefficient ot thermal expansion and relatively rapid heat',conductivity and for the purposes ol' illustration, I shall describe the head 3 ot this specification as made of aluminum. The head 3 is formed with exterior grooves it to receive the usual piston rings 5; has a. pair of integral diametrically opposed downwardly extending lugs G formed with integral inwardly extending bosses adapted to receive and accommo-` date the usual piston wrist pin 8. A reinforcing, rib 9 'is formed integrally with the head. 3 and runs transversely across the inner face oi the latter and is provided with integral downwardly extending portions 9 integrally connecting withi` the upper part of the wrist pin bosses 7, as plainly shown in Figure 4.

.l shall now describe means for connect- For this purpose l form the head 3 with an annular series of downwardly extending ears 10 vvhich are secured to the skirt 2 and as illustrating one approved method of so securing these ears 10 l show thesame provided with tapped holes for receiving suitable screws ll which are passed through the Wall of the skirt 2 adjaccntly the upper edge of the latter and are preferably counter-sunk `in said wall, as plainly'shown Preferably, the aluminum head 3 is somewhat smaller in diameter than the' skirt 2,

approximately .01() inch to .015 inch smaller so that whereas the skirt 2 has a running fit in the cylinder l, the aluminum head 3 can expand the necessary amount greater than the expansion et the cast-iron skirt 2. My means for connecting the skirt 2 and head 3 are very efficient and vet adequately provide for the necessary adjustment of the head and skirt, due to their diilerent coefficients ot expansion, the ears 10 having enough spring to compensate for this difference of expansion between the bot-tom of the head Il and the top ot the skirt 2. Preferahly,the llexible ears l() are east integrally with the aluminum head 3. Preferably, although not, necessarily, l undercut the ears Il), as indicated by the ordinal 12, better t0 allow for the necessary spring of these ears when compensating for the different expansions of the skirt 2 and head 3.'

What I claim is:

1. A piston for an internal combustion engine comprising a guide section and a head section of different materials; and flexible means for securing together said two sections, whereby adjustment is allowed for the differential in expansion.

2. A piston for an internal combustion engine comprising a guide section and a head section of dlfferent materials, one of said sections being formed with fiexible ears; and means for securing said ears to the other section, wherebyadjustment is allowed for the differential in expansion.

3. A pistonv fot? an internal combustion engine comprisingya guide section ol material having a reliftively low coefficient of thermal expansion; a head section of' material having a relatively .high coefficient of' thermal expansion, said head section being formed with a series ofA flexible ears; and means for securing said ears to said guide section, whereby adjustment is allowed for the differential in expansion.

4. A piston for an internal combustion engine comprising a cast-iron guide section; an aluminum head section formed with a series of integrally cast flexible ears; and means for securing said ears to said 'guide section, whereby adjust-ment is allowed for the differential in expansion.-

5. A piston for an internal combustion engine comprising 4a cast-iron guide section; an aluminum head section, the latter being formed with a series of downwardly extending tapped fiexible ears; and screws secur ing said ears to said guide section, whereby adjustment is allowed for the differential in expansion.

6. A piston for an internal combustion engine comprising a cast-iron guide section; an aluminum head section of smaller diameter; and flexible means Afor securing together said two sections, whereby adjustment'is allowed for the differential in expansion.

7. 51 piston for an internal combustion engine comprising a cast-iron guide section; an aluminum head section of smaller` diameter, said head section being formed with a series of' downwardly extending tapped flexible ears; and screws securin said ears to said guide section` whereby ajustinent is allowed for the differential in expansion. 4

8. A piston for an internal combustion engine comprising a cast-iron guide section; an aluminum head section, the latter'being formed with a series of downwardly extended ears having undercut grooves in the seetions joining the ears to the head; and.

means for securing said ears to said guide section.

Signed by me this 12th day of December,

RUSSELL J. VOODRUFF. 

